xen/blkback: Use the DRV_PFX in the pr_.. macros.
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / drivers / scsi / libfc / fc_exch.c
blob77035a746f6027e5f232140349e7339c5901f2e9
1 /*
2 * Copyright(c) 2007 Intel Corporation. All rights reserved.
3 * Copyright(c) 2008 Red Hat, Inc. All rights reserved.
4 * Copyright(c) 2008 Mike Christie
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19 * Maintained at www.Open-FCoE.org
23 * Fibre Channel exchange and sequence handling.
26 #include <linux/timer.h>
27 #include <linux/slab.h>
28 #include <linux/err.h>
30 #include <scsi/fc/fc_fc2.h>
32 #include <scsi/libfc.h>
33 #include <scsi/fc_encode.h>
35 #include "fc_libfc.h"
37 u16 fc_cpu_mask; /* cpu mask for possible cpus */
38 EXPORT_SYMBOL(fc_cpu_mask);
39 static u16 fc_cpu_order; /* 2's power to represent total possible cpus */
40 static struct kmem_cache *fc_em_cachep; /* cache for exchanges */
41 static struct workqueue_struct *fc_exch_workqueue;
44 * Structure and function definitions for managing Fibre Channel Exchanges
45 * and Sequences.
47 * The three primary structures used here are fc_exch_mgr, fc_exch, and fc_seq.
49 * fc_exch_mgr holds the exchange state for an N port
51 * fc_exch holds state for one exchange and links to its active sequence.
53 * fc_seq holds the state for an individual sequence.
56 /**
57 * struct fc_exch_pool - Per cpu exchange pool
58 * @next_index: Next possible free exchange index
59 * @total_exches: Total allocated exchanges
60 * @lock: Exch pool lock
61 * @ex_list: List of exchanges
63 * This structure manages per cpu exchanges in array of exchange pointers.
64 * This array is allocated followed by struct fc_exch_pool memory for
65 * assigned range of exchanges to per cpu pool.
67 struct fc_exch_pool {
68 u16 next_index;
69 u16 total_exches;
71 /* two cache of free slot in exch array */
72 u16 left;
73 u16 right;
75 spinlock_t lock;
76 struct list_head ex_list;
79 /**
80 * struct fc_exch_mgr - The Exchange Manager (EM).
81 * @class: Default class for new sequences
82 * @kref: Reference counter
83 * @min_xid: Minimum exchange ID
84 * @max_xid: Maximum exchange ID
85 * @ep_pool: Reserved exchange pointers
86 * @pool_max_index: Max exch array index in exch pool
87 * @pool: Per cpu exch pool
88 * @stats: Statistics structure
90 * This structure is the center for creating exchanges and sequences.
91 * It manages the allocation of exchange IDs.
93 struct fc_exch_mgr {
94 enum fc_class class;
95 struct kref kref;
96 u16 min_xid;
97 u16 max_xid;
98 mempool_t *ep_pool;
99 u16 pool_max_index;
100 struct fc_exch_pool *pool;
103 * currently exchange mgr stats are updated but not used.
104 * either stats can be expose via sysfs or remove them
105 * all together if not used XXX
107 struct {
108 atomic_t no_free_exch;
109 atomic_t no_free_exch_xid;
110 atomic_t xid_not_found;
111 atomic_t xid_busy;
112 atomic_t seq_not_found;
113 atomic_t non_bls_resp;
114 } stats;
118 * struct fc_exch_mgr_anchor - primary structure for list of EMs
119 * @ema_list: Exchange Manager Anchor list
120 * @mp: Exchange Manager associated with this anchor
121 * @match: Routine to determine if this anchor's EM should be used
123 * When walking the list of anchors the match routine will be called
124 * for each anchor to determine if that EM should be used. The last
125 * anchor in the list will always match to handle any exchanges not
126 * handled by other EMs. The non-default EMs would be added to the
127 * anchor list by HW that provides FCoE offloads.
129 struct fc_exch_mgr_anchor {
130 struct list_head ema_list;
131 struct fc_exch_mgr *mp;
132 bool (*match)(struct fc_frame *);
135 static void fc_exch_rrq(struct fc_exch *);
136 static void fc_seq_ls_acc(struct fc_frame *);
137 static void fc_seq_ls_rjt(struct fc_frame *, enum fc_els_rjt_reason,
138 enum fc_els_rjt_explan);
139 static void fc_exch_els_rec(struct fc_frame *);
140 static void fc_exch_els_rrq(struct fc_frame *);
143 * Internal implementation notes.
145 * The exchange manager is one by default in libfc but LLD may choose
146 * to have one per CPU. The sequence manager is one per exchange manager
147 * and currently never separated.
149 * Section 9.8 in FC-FS-2 specifies: "The SEQ_ID is a one-byte field
150 * assigned by the Sequence Initiator that shall be unique for a specific
151 * D_ID and S_ID pair while the Sequence is open." Note that it isn't
152 * qualified by exchange ID, which one might think it would be.
153 * In practice this limits the number of open sequences and exchanges to 256
154 * per session. For most targets we could treat this limit as per exchange.
156 * The exchange and its sequence are freed when the last sequence is received.
157 * It's possible for the remote port to leave an exchange open without
158 * sending any sequences.
160 * Notes on reference counts:
162 * Exchanges are reference counted and exchange gets freed when the reference
163 * count becomes zero.
165 * Timeouts:
166 * Sequences are timed out for E_D_TOV and R_A_TOV.
168 * Sequence event handling:
170 * The following events may occur on initiator sequences:
172 * Send.
173 * For now, the whole thing is sent.
174 * Receive ACK
175 * This applies only to class F.
176 * The sequence is marked complete.
177 * ULP completion.
178 * The upper layer calls fc_exch_done() when done
179 * with exchange and sequence tuple.
180 * RX-inferred completion.
181 * When we receive the next sequence on the same exchange, we can
182 * retire the previous sequence ID. (XXX not implemented).
183 * Timeout.
184 * R_A_TOV frees the sequence ID. If we're waiting for ACK,
185 * E_D_TOV causes abort and calls upper layer response handler
186 * with FC_EX_TIMEOUT error.
187 * Receive RJT
188 * XXX defer.
189 * Send ABTS
190 * On timeout.
192 * The following events may occur on recipient sequences:
194 * Receive
195 * Allocate sequence for first frame received.
196 * Hold during receive handler.
197 * Release when final frame received.
198 * Keep status of last N of these for the ELS RES command. XXX TBD.
199 * Receive ABTS
200 * Deallocate sequence
201 * Send RJT
202 * Deallocate
204 * For now, we neglect conditions where only part of a sequence was
205 * received or transmitted, or where out-of-order receipt is detected.
209 * Locking notes:
211 * The EM code run in a per-CPU worker thread.
213 * To protect against concurrency between a worker thread code and timers,
214 * sequence allocation and deallocation must be locked.
215 * - exchange refcnt can be done atomicly without locks.
216 * - sequence allocation must be locked by exch lock.
217 * - If the EM pool lock and ex_lock must be taken at the same time, then the
218 * EM pool lock must be taken before the ex_lock.
222 * opcode names for debugging.
224 static char *fc_exch_rctl_names[] = FC_RCTL_NAMES_INIT;
227 * fc_exch_name_lookup() - Lookup name by opcode
228 * @op: Opcode to be looked up
229 * @table: Opcode/name table
230 * @max_index: Index not to be exceeded
232 * This routine is used to determine a human-readable string identifying
233 * a R_CTL opcode.
235 static inline const char *fc_exch_name_lookup(unsigned int op, char **table,
236 unsigned int max_index)
238 const char *name = NULL;
240 if (op < max_index)
241 name = table[op];
242 if (!name)
243 name = "unknown";
244 return name;
248 * fc_exch_rctl_name() - Wrapper routine for fc_exch_name_lookup()
249 * @op: The opcode to be looked up
251 static const char *fc_exch_rctl_name(unsigned int op)
253 return fc_exch_name_lookup(op, fc_exch_rctl_names,
254 ARRAY_SIZE(fc_exch_rctl_names));
258 * fc_exch_hold() - Increment an exchange's reference count
259 * @ep: Echange to be held
261 static inline void fc_exch_hold(struct fc_exch *ep)
263 atomic_inc(&ep->ex_refcnt);
267 * fc_exch_setup_hdr() - Initialize a FC header by initializing some fields
268 * and determine SOF and EOF.
269 * @ep: The exchange to that will use the header
270 * @fp: The frame whose header is to be modified
271 * @f_ctl: F_CTL bits that will be used for the frame header
273 * The fields initialized by this routine are: fh_ox_id, fh_rx_id,
274 * fh_seq_id, fh_seq_cnt and the SOF and EOF.
276 static void fc_exch_setup_hdr(struct fc_exch *ep, struct fc_frame *fp,
277 u32 f_ctl)
279 struct fc_frame_header *fh = fc_frame_header_get(fp);
280 u16 fill;
282 fr_sof(fp) = ep->class;
283 if (ep->seq.cnt)
284 fr_sof(fp) = fc_sof_normal(ep->class);
286 if (f_ctl & FC_FC_END_SEQ) {
287 fr_eof(fp) = FC_EOF_T;
288 if (fc_sof_needs_ack(ep->class))
289 fr_eof(fp) = FC_EOF_N;
291 * From F_CTL.
292 * The number of fill bytes to make the length a 4-byte
293 * multiple is the low order 2-bits of the f_ctl.
294 * The fill itself will have been cleared by the frame
295 * allocation.
296 * After this, the length will be even, as expected by
297 * the transport.
299 fill = fr_len(fp) & 3;
300 if (fill) {
301 fill = 4 - fill;
302 /* TODO, this may be a problem with fragmented skb */
303 skb_put(fp_skb(fp), fill);
304 hton24(fh->fh_f_ctl, f_ctl | fill);
306 } else {
307 WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
308 fr_eof(fp) = FC_EOF_N;
312 * Initialize remainig fh fields
313 * from fc_fill_fc_hdr
315 fh->fh_ox_id = htons(ep->oxid);
316 fh->fh_rx_id = htons(ep->rxid);
317 fh->fh_seq_id = ep->seq.id;
318 fh->fh_seq_cnt = htons(ep->seq.cnt);
322 * fc_exch_release() - Decrement an exchange's reference count
323 * @ep: Exchange to be released
325 * If the reference count reaches zero and the exchange is complete,
326 * it is freed.
328 static void fc_exch_release(struct fc_exch *ep)
330 struct fc_exch_mgr *mp;
332 if (atomic_dec_and_test(&ep->ex_refcnt)) {
333 mp = ep->em;
334 if (ep->destructor)
335 ep->destructor(&ep->seq, ep->arg);
336 WARN_ON(!(ep->esb_stat & ESB_ST_COMPLETE));
337 mempool_free(ep, mp->ep_pool);
342 * fc_exch_done_locked() - Complete an exchange with the exchange lock held
343 * @ep: The exchange that is complete
345 static int fc_exch_done_locked(struct fc_exch *ep)
347 int rc = 1;
350 * We must check for completion in case there are two threads
351 * tyring to complete this. But the rrq code will reuse the
352 * ep, and in that case we only clear the resp and set it as
353 * complete, so it can be reused by the timer to send the rrq.
355 ep->resp = NULL;
356 if (ep->state & FC_EX_DONE)
357 return rc;
358 ep->esb_stat |= ESB_ST_COMPLETE;
360 if (!(ep->esb_stat & ESB_ST_REC_QUAL)) {
361 ep->state |= FC_EX_DONE;
362 if (cancel_delayed_work(&ep->timeout_work))
363 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
364 rc = 0;
366 return rc;
370 * fc_exch_ptr_get() - Return an exchange from an exchange pool
371 * @pool: Exchange Pool to get an exchange from
372 * @index: Index of the exchange within the pool
374 * Use the index to get an exchange from within an exchange pool. exches
375 * will point to an array of exchange pointers. The index will select
376 * the exchange within the array.
378 static inline struct fc_exch *fc_exch_ptr_get(struct fc_exch_pool *pool,
379 u16 index)
381 struct fc_exch **exches = (struct fc_exch **)(pool + 1);
382 return exches[index];
386 * fc_exch_ptr_set() - Assign an exchange to a slot in an exchange pool
387 * @pool: The pool to assign the exchange to
388 * @index: The index in the pool where the exchange will be assigned
389 * @ep: The exchange to assign to the pool
391 static inline void fc_exch_ptr_set(struct fc_exch_pool *pool, u16 index,
392 struct fc_exch *ep)
394 ((struct fc_exch **)(pool + 1))[index] = ep;
398 * fc_exch_delete() - Delete an exchange
399 * @ep: The exchange to be deleted
401 static void fc_exch_delete(struct fc_exch *ep)
403 struct fc_exch_pool *pool;
404 u16 index;
406 pool = ep->pool;
407 spin_lock_bh(&pool->lock);
408 WARN_ON(pool->total_exches <= 0);
409 pool->total_exches--;
411 /* update cache of free slot */
412 index = (ep->xid - ep->em->min_xid) >> fc_cpu_order;
413 if (pool->left == FC_XID_UNKNOWN)
414 pool->left = index;
415 else if (pool->right == FC_XID_UNKNOWN)
416 pool->right = index;
417 else
418 pool->next_index = index;
420 fc_exch_ptr_set(pool, index, NULL);
421 list_del(&ep->ex_list);
422 spin_unlock_bh(&pool->lock);
423 fc_exch_release(ep); /* drop hold for exch in mp */
427 * fc_exch_timer_set_locked() - Start a timer for an exchange w/ the
428 * the exchange lock held
429 * @ep: The exchange whose timer will start
430 * @timer_msec: The timeout period
432 * Used for upper level protocols to time out the exchange.
433 * The timer is cancelled when it fires or when the exchange completes.
435 static inline void fc_exch_timer_set_locked(struct fc_exch *ep,
436 unsigned int timer_msec)
438 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
439 return;
441 FC_EXCH_DBG(ep, "Exchange timer armed\n");
443 if (queue_delayed_work(fc_exch_workqueue, &ep->timeout_work,
444 msecs_to_jiffies(timer_msec)))
445 fc_exch_hold(ep); /* hold for timer */
449 * fc_exch_timer_set() - Lock the exchange and set the timer
450 * @ep: The exchange whose timer will start
451 * @timer_msec: The timeout period
453 static void fc_exch_timer_set(struct fc_exch *ep, unsigned int timer_msec)
455 spin_lock_bh(&ep->ex_lock);
456 fc_exch_timer_set_locked(ep, timer_msec);
457 spin_unlock_bh(&ep->ex_lock);
461 * fc_seq_send() - Send a frame using existing sequence/exchange pair
462 * @lport: The local port that the exchange will be sent on
463 * @sp: The sequence to be sent
464 * @fp: The frame to be sent on the exchange
466 static int fc_seq_send(struct fc_lport *lport, struct fc_seq *sp,
467 struct fc_frame *fp)
469 struct fc_exch *ep;
470 struct fc_frame_header *fh = fc_frame_header_get(fp);
471 int error;
472 u32 f_ctl;
474 ep = fc_seq_exch(sp);
475 WARN_ON((ep->esb_stat & ESB_ST_SEQ_INIT) != ESB_ST_SEQ_INIT);
477 f_ctl = ntoh24(fh->fh_f_ctl);
478 fc_exch_setup_hdr(ep, fp, f_ctl);
479 fr_encaps(fp) = ep->encaps;
482 * update sequence count if this frame is carrying
483 * multiple FC frames when sequence offload is enabled
484 * by LLD.
486 if (fr_max_payload(fp))
487 sp->cnt += DIV_ROUND_UP((fr_len(fp) - sizeof(*fh)),
488 fr_max_payload(fp));
489 else
490 sp->cnt++;
493 * Send the frame.
495 error = lport->tt.frame_send(lport, fp);
498 * Update the exchange and sequence flags,
499 * assuming all frames for the sequence have been sent.
500 * We can only be called to send once for each sequence.
502 spin_lock_bh(&ep->ex_lock);
503 ep->f_ctl = f_ctl & ~FC_FC_FIRST_SEQ; /* not first seq */
504 if (f_ctl & FC_FC_SEQ_INIT)
505 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
506 spin_unlock_bh(&ep->ex_lock);
507 return error;
511 * fc_seq_alloc() - Allocate a sequence for a given exchange
512 * @ep: The exchange to allocate a new sequence for
513 * @seq_id: The sequence ID to be used
515 * We don't support multiple originated sequences on the same exchange.
516 * By implication, any previously originated sequence on this exchange
517 * is complete, and we reallocate the same sequence.
519 static struct fc_seq *fc_seq_alloc(struct fc_exch *ep, u8 seq_id)
521 struct fc_seq *sp;
523 sp = &ep->seq;
524 sp->ssb_stat = 0;
525 sp->cnt = 0;
526 sp->id = seq_id;
527 return sp;
531 * fc_seq_start_next_locked() - Allocate a new sequence on the same
532 * exchange as the supplied sequence
533 * @sp: The sequence/exchange to get a new sequence for
535 static struct fc_seq *fc_seq_start_next_locked(struct fc_seq *sp)
537 struct fc_exch *ep = fc_seq_exch(sp);
539 sp = fc_seq_alloc(ep, ep->seq_id++);
540 FC_EXCH_DBG(ep, "f_ctl %6x seq %2x\n",
541 ep->f_ctl, sp->id);
542 return sp;
546 * fc_seq_start_next() - Lock the exchange and get a new sequence
547 * for a given sequence/exchange pair
548 * @sp: The sequence/exchange to get a new exchange for
550 static struct fc_seq *fc_seq_start_next(struct fc_seq *sp)
552 struct fc_exch *ep = fc_seq_exch(sp);
554 spin_lock_bh(&ep->ex_lock);
555 sp = fc_seq_start_next_locked(sp);
556 spin_unlock_bh(&ep->ex_lock);
558 return sp;
562 * Set the response handler for the exchange associated with a sequence.
564 static void fc_seq_set_resp(struct fc_seq *sp,
565 void (*resp)(struct fc_seq *, struct fc_frame *,
566 void *),
567 void *arg)
569 struct fc_exch *ep = fc_seq_exch(sp);
571 spin_lock_bh(&ep->ex_lock);
572 ep->resp = resp;
573 ep->arg = arg;
574 spin_unlock_bh(&ep->ex_lock);
578 * fc_seq_exch_abort() - Abort an exchange and sequence
579 * @req_sp: The sequence to be aborted
580 * @timer_msec: The period of time to wait before aborting
582 * Generally called because of a timeout or an abort from the upper layer.
584 static int fc_seq_exch_abort(const struct fc_seq *req_sp,
585 unsigned int timer_msec)
587 struct fc_seq *sp;
588 struct fc_exch *ep;
589 struct fc_frame *fp;
590 int error;
592 ep = fc_seq_exch(req_sp);
594 spin_lock_bh(&ep->ex_lock);
595 if (ep->esb_stat & (ESB_ST_COMPLETE | ESB_ST_ABNORMAL) ||
596 ep->state & (FC_EX_DONE | FC_EX_RST_CLEANUP)) {
597 spin_unlock_bh(&ep->ex_lock);
598 return -ENXIO;
602 * Send the abort on a new sequence if possible.
604 sp = fc_seq_start_next_locked(&ep->seq);
605 if (!sp) {
606 spin_unlock_bh(&ep->ex_lock);
607 return -ENOMEM;
610 ep->esb_stat |= ESB_ST_SEQ_INIT | ESB_ST_ABNORMAL;
611 if (timer_msec)
612 fc_exch_timer_set_locked(ep, timer_msec);
613 spin_unlock_bh(&ep->ex_lock);
616 * If not logged into the fabric, don't send ABTS but leave
617 * sequence active until next timeout.
619 if (!ep->sid)
620 return 0;
623 * Send an abort for the sequence that timed out.
625 fp = fc_frame_alloc(ep->lp, 0);
626 if (fp) {
627 fc_fill_fc_hdr(fp, FC_RCTL_BA_ABTS, ep->did, ep->sid,
628 FC_TYPE_BLS, FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
629 error = fc_seq_send(ep->lp, sp, fp);
630 } else
631 error = -ENOBUFS;
632 return error;
636 * fc_exch_timeout() - Handle exchange timer expiration
637 * @work: The work_struct identifying the exchange that timed out
639 static void fc_exch_timeout(struct work_struct *work)
641 struct fc_exch *ep = container_of(work, struct fc_exch,
642 timeout_work.work);
643 struct fc_seq *sp = &ep->seq;
644 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
645 void *arg;
646 u32 e_stat;
647 int rc = 1;
649 FC_EXCH_DBG(ep, "Exchange timed out\n");
651 spin_lock_bh(&ep->ex_lock);
652 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE))
653 goto unlock;
655 e_stat = ep->esb_stat;
656 if (e_stat & ESB_ST_COMPLETE) {
657 ep->esb_stat = e_stat & ~ESB_ST_REC_QUAL;
658 spin_unlock_bh(&ep->ex_lock);
659 if (e_stat & ESB_ST_REC_QUAL)
660 fc_exch_rrq(ep);
661 goto done;
662 } else {
663 resp = ep->resp;
664 arg = ep->arg;
665 ep->resp = NULL;
666 if (e_stat & ESB_ST_ABNORMAL)
667 rc = fc_exch_done_locked(ep);
668 spin_unlock_bh(&ep->ex_lock);
669 if (!rc)
670 fc_exch_delete(ep);
671 if (resp)
672 resp(sp, ERR_PTR(-FC_EX_TIMEOUT), arg);
673 fc_seq_exch_abort(sp, 2 * ep->r_a_tov);
674 goto done;
676 unlock:
677 spin_unlock_bh(&ep->ex_lock);
678 done:
680 * This release matches the hold taken when the timer was set.
682 fc_exch_release(ep);
686 * fc_exch_em_alloc() - Allocate an exchange from a specified EM.
687 * @lport: The local port that the exchange is for
688 * @mp: The exchange manager that will allocate the exchange
690 * Returns pointer to allocated fc_exch with exch lock held.
692 static struct fc_exch *fc_exch_em_alloc(struct fc_lport *lport,
693 struct fc_exch_mgr *mp)
695 struct fc_exch *ep;
696 unsigned int cpu;
697 u16 index;
698 struct fc_exch_pool *pool;
700 /* allocate memory for exchange */
701 ep = mempool_alloc(mp->ep_pool, GFP_ATOMIC);
702 if (!ep) {
703 atomic_inc(&mp->stats.no_free_exch);
704 goto out;
706 memset(ep, 0, sizeof(*ep));
708 cpu = get_cpu();
709 pool = per_cpu_ptr(mp->pool, cpu);
710 spin_lock_bh(&pool->lock);
711 put_cpu();
713 /* peek cache of free slot */
714 if (pool->left != FC_XID_UNKNOWN) {
715 index = pool->left;
716 pool->left = FC_XID_UNKNOWN;
717 goto hit;
719 if (pool->right != FC_XID_UNKNOWN) {
720 index = pool->right;
721 pool->right = FC_XID_UNKNOWN;
722 goto hit;
725 index = pool->next_index;
726 /* allocate new exch from pool */
727 while (fc_exch_ptr_get(pool, index)) {
728 index = index == mp->pool_max_index ? 0 : index + 1;
729 if (index == pool->next_index)
730 goto err;
732 pool->next_index = index == mp->pool_max_index ? 0 : index + 1;
733 hit:
734 fc_exch_hold(ep); /* hold for exch in mp */
735 spin_lock_init(&ep->ex_lock);
737 * Hold exch lock for caller to prevent fc_exch_reset()
738 * from releasing exch while fc_exch_alloc() caller is
739 * still working on exch.
741 spin_lock_bh(&ep->ex_lock);
743 fc_exch_ptr_set(pool, index, ep);
744 list_add_tail(&ep->ex_list, &pool->ex_list);
745 fc_seq_alloc(ep, ep->seq_id++);
746 pool->total_exches++;
747 spin_unlock_bh(&pool->lock);
750 * update exchange
752 ep->oxid = ep->xid = (index << fc_cpu_order | cpu) + mp->min_xid;
753 ep->em = mp;
754 ep->pool = pool;
755 ep->lp = lport;
756 ep->f_ctl = FC_FC_FIRST_SEQ; /* next seq is first seq */
757 ep->rxid = FC_XID_UNKNOWN;
758 ep->class = mp->class;
759 INIT_DELAYED_WORK(&ep->timeout_work, fc_exch_timeout);
760 out:
761 return ep;
762 err:
763 spin_unlock_bh(&pool->lock);
764 atomic_inc(&mp->stats.no_free_exch_xid);
765 mempool_free(ep, mp->ep_pool);
766 return NULL;
770 * fc_exch_alloc() - Allocate an exchange from an EM on a
771 * local port's list of EMs.
772 * @lport: The local port that will own the exchange
773 * @fp: The FC frame that the exchange will be for
775 * This function walks the list of exchange manager(EM)
776 * anchors to select an EM for a new exchange allocation. The
777 * EM is selected when a NULL match function pointer is encountered
778 * or when a call to a match function returns true.
780 static inline struct fc_exch *fc_exch_alloc(struct fc_lport *lport,
781 struct fc_frame *fp)
783 struct fc_exch_mgr_anchor *ema;
785 list_for_each_entry(ema, &lport->ema_list, ema_list)
786 if (!ema->match || ema->match(fp))
787 return fc_exch_em_alloc(lport, ema->mp);
788 return NULL;
792 * fc_exch_find() - Lookup and hold an exchange
793 * @mp: The exchange manager to lookup the exchange from
794 * @xid: The XID of the exchange to look up
796 static struct fc_exch *fc_exch_find(struct fc_exch_mgr *mp, u16 xid)
798 struct fc_exch_pool *pool;
799 struct fc_exch *ep = NULL;
801 if ((xid >= mp->min_xid) && (xid <= mp->max_xid)) {
802 pool = per_cpu_ptr(mp->pool, xid & fc_cpu_mask);
803 spin_lock_bh(&pool->lock);
804 ep = fc_exch_ptr_get(pool, (xid - mp->min_xid) >> fc_cpu_order);
805 if (ep) {
806 fc_exch_hold(ep);
807 WARN_ON(ep->xid != xid);
809 spin_unlock_bh(&pool->lock);
811 return ep;
816 * fc_exch_done() - Indicate that an exchange/sequence tuple is complete and
817 * the memory allocated for the related objects may be freed.
818 * @sp: The sequence that has completed
820 static void fc_exch_done(struct fc_seq *sp)
822 struct fc_exch *ep = fc_seq_exch(sp);
823 int rc;
825 spin_lock_bh(&ep->ex_lock);
826 rc = fc_exch_done_locked(ep);
827 spin_unlock_bh(&ep->ex_lock);
828 if (!rc)
829 fc_exch_delete(ep);
833 * fc_exch_resp() - Allocate a new exchange for a response frame
834 * @lport: The local port that the exchange was for
835 * @mp: The exchange manager to allocate the exchange from
836 * @fp: The response frame
838 * Sets the responder ID in the frame header.
840 static struct fc_exch *fc_exch_resp(struct fc_lport *lport,
841 struct fc_exch_mgr *mp,
842 struct fc_frame *fp)
844 struct fc_exch *ep;
845 struct fc_frame_header *fh;
847 ep = fc_exch_alloc(lport, fp);
848 if (ep) {
849 ep->class = fc_frame_class(fp);
852 * Set EX_CTX indicating we're responding on this exchange.
854 ep->f_ctl |= FC_FC_EX_CTX; /* we're responding */
855 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not new */
856 fh = fc_frame_header_get(fp);
857 ep->sid = ntoh24(fh->fh_d_id);
858 ep->did = ntoh24(fh->fh_s_id);
859 ep->oid = ep->did;
862 * Allocated exchange has placed the XID in the
863 * originator field. Move it to the responder field,
864 * and set the originator XID from the frame.
866 ep->rxid = ep->xid;
867 ep->oxid = ntohs(fh->fh_ox_id);
868 ep->esb_stat |= ESB_ST_RESP | ESB_ST_SEQ_INIT;
869 if ((ntoh24(fh->fh_f_ctl) & FC_FC_SEQ_INIT) == 0)
870 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
872 fc_exch_hold(ep); /* hold for caller */
873 spin_unlock_bh(&ep->ex_lock); /* lock from fc_exch_alloc */
875 return ep;
879 * fc_seq_lookup_recip() - Find a sequence where the other end
880 * originated the sequence
881 * @lport: The local port that the frame was sent to
882 * @mp: The Exchange Manager to lookup the exchange from
883 * @fp: The frame associated with the sequence we're looking for
885 * If fc_pf_rjt_reason is FC_RJT_NONE then this function will have a hold
886 * on the ep that should be released by the caller.
888 static enum fc_pf_rjt_reason fc_seq_lookup_recip(struct fc_lport *lport,
889 struct fc_exch_mgr *mp,
890 struct fc_frame *fp)
892 struct fc_frame_header *fh = fc_frame_header_get(fp);
893 struct fc_exch *ep = NULL;
894 struct fc_seq *sp = NULL;
895 enum fc_pf_rjt_reason reject = FC_RJT_NONE;
896 u32 f_ctl;
897 u16 xid;
899 f_ctl = ntoh24(fh->fh_f_ctl);
900 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != 0);
903 * Lookup or create the exchange if we will be creating the sequence.
905 if (f_ctl & FC_FC_EX_CTX) {
906 xid = ntohs(fh->fh_ox_id); /* we originated exch */
907 ep = fc_exch_find(mp, xid);
908 if (!ep) {
909 atomic_inc(&mp->stats.xid_not_found);
910 reject = FC_RJT_OX_ID;
911 goto out;
913 if (ep->rxid == FC_XID_UNKNOWN)
914 ep->rxid = ntohs(fh->fh_rx_id);
915 else if (ep->rxid != ntohs(fh->fh_rx_id)) {
916 reject = FC_RJT_OX_ID;
917 goto rel;
919 } else {
920 xid = ntohs(fh->fh_rx_id); /* we are the responder */
923 * Special case for MDS issuing an ELS TEST with a
924 * bad rxid of 0.
925 * XXX take this out once we do the proper reject.
927 if (xid == 0 && fh->fh_r_ctl == FC_RCTL_ELS_REQ &&
928 fc_frame_payload_op(fp) == ELS_TEST) {
929 fh->fh_rx_id = htons(FC_XID_UNKNOWN);
930 xid = FC_XID_UNKNOWN;
934 * new sequence - find the exchange
936 ep = fc_exch_find(mp, xid);
937 if ((f_ctl & FC_FC_FIRST_SEQ) && fc_sof_is_init(fr_sof(fp))) {
938 if (ep) {
939 atomic_inc(&mp->stats.xid_busy);
940 reject = FC_RJT_RX_ID;
941 goto rel;
943 ep = fc_exch_resp(lport, mp, fp);
944 if (!ep) {
945 reject = FC_RJT_EXCH_EST; /* XXX */
946 goto out;
948 xid = ep->xid; /* get our XID */
949 } else if (!ep) {
950 atomic_inc(&mp->stats.xid_not_found);
951 reject = FC_RJT_RX_ID; /* XID not found */
952 goto out;
957 * At this point, we have the exchange held.
958 * Find or create the sequence.
960 if (fc_sof_is_init(fr_sof(fp))) {
961 sp = &ep->seq;
962 sp->ssb_stat |= SSB_ST_RESP;
963 sp->id = fh->fh_seq_id;
964 } else {
965 sp = &ep->seq;
966 if (sp->id != fh->fh_seq_id) {
967 atomic_inc(&mp->stats.seq_not_found);
968 reject = FC_RJT_SEQ_ID; /* sequence/exch should exist */
969 goto rel;
972 WARN_ON(ep != fc_seq_exch(sp));
974 if (f_ctl & FC_FC_SEQ_INIT)
975 ep->esb_stat |= ESB_ST_SEQ_INIT;
977 fr_seq(fp) = sp;
978 out:
979 return reject;
980 rel:
981 fc_exch_done(&ep->seq);
982 fc_exch_release(ep); /* hold from fc_exch_find/fc_exch_resp */
983 return reject;
987 * fc_seq_lookup_orig() - Find a sequence where this end
988 * originated the sequence
989 * @mp: The Exchange Manager to lookup the exchange from
990 * @fp: The frame associated with the sequence we're looking for
992 * Does not hold the sequence for the caller.
994 static struct fc_seq *fc_seq_lookup_orig(struct fc_exch_mgr *mp,
995 struct fc_frame *fp)
997 struct fc_frame_header *fh = fc_frame_header_get(fp);
998 struct fc_exch *ep;
999 struct fc_seq *sp = NULL;
1000 u32 f_ctl;
1001 u16 xid;
1003 f_ctl = ntoh24(fh->fh_f_ctl);
1004 WARN_ON((f_ctl & FC_FC_SEQ_CTX) != FC_FC_SEQ_CTX);
1005 xid = ntohs((f_ctl & FC_FC_EX_CTX) ? fh->fh_ox_id : fh->fh_rx_id);
1006 ep = fc_exch_find(mp, xid);
1007 if (!ep)
1008 return NULL;
1009 if (ep->seq.id == fh->fh_seq_id) {
1011 * Save the RX_ID if we didn't previously know it.
1013 sp = &ep->seq;
1014 if ((f_ctl & FC_FC_EX_CTX) != 0 &&
1015 ep->rxid == FC_XID_UNKNOWN) {
1016 ep->rxid = ntohs(fh->fh_rx_id);
1019 fc_exch_release(ep);
1020 return sp;
1024 * fc_exch_set_addr() - Set the source and destination IDs for an exchange
1025 * @ep: The exchange to set the addresses for
1026 * @orig_id: The originator's ID
1027 * @resp_id: The responder's ID
1029 * Note this must be done before the first sequence of the exchange is sent.
1031 static void fc_exch_set_addr(struct fc_exch *ep,
1032 u32 orig_id, u32 resp_id)
1034 ep->oid = orig_id;
1035 if (ep->esb_stat & ESB_ST_RESP) {
1036 ep->sid = resp_id;
1037 ep->did = orig_id;
1038 } else {
1039 ep->sid = orig_id;
1040 ep->did = resp_id;
1045 * fc_seq_els_rsp_send() - Send an ELS response using information from
1046 * the existing sequence/exchange.
1047 * @fp: The received frame
1048 * @els_cmd: The ELS command to be sent
1049 * @els_data: The ELS data to be sent
1051 * The received frame is not freed.
1053 static void fc_seq_els_rsp_send(struct fc_frame *fp, enum fc_els_cmd els_cmd,
1054 struct fc_seq_els_data *els_data)
1056 switch (els_cmd) {
1057 case ELS_LS_RJT:
1058 fc_seq_ls_rjt(fp, els_data->reason, els_data->explan);
1059 break;
1060 case ELS_LS_ACC:
1061 fc_seq_ls_acc(fp);
1062 break;
1063 case ELS_RRQ:
1064 fc_exch_els_rrq(fp);
1065 break;
1066 case ELS_REC:
1067 fc_exch_els_rec(fp);
1068 break;
1069 default:
1070 FC_LPORT_DBG(fr_dev(fp), "Invalid ELS CMD:%x\n", els_cmd);
1075 * fc_seq_send_last() - Send a sequence that is the last in the exchange
1076 * @sp: The sequence that is to be sent
1077 * @fp: The frame that will be sent on the sequence
1078 * @rctl: The R_CTL information to be sent
1079 * @fh_type: The frame header type
1081 static void fc_seq_send_last(struct fc_seq *sp, struct fc_frame *fp,
1082 enum fc_rctl rctl, enum fc_fh_type fh_type)
1084 u32 f_ctl;
1085 struct fc_exch *ep = fc_seq_exch(sp);
1087 f_ctl = FC_FC_LAST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT;
1088 f_ctl |= ep->f_ctl;
1089 fc_fill_fc_hdr(fp, rctl, ep->did, ep->sid, fh_type, f_ctl, 0);
1090 fc_seq_send(ep->lp, sp, fp);
1094 * fc_seq_send_ack() - Send an acknowledgement that we've received a frame
1095 * @sp: The sequence to send the ACK on
1096 * @rx_fp: The received frame that is being acknoledged
1098 * Send ACK_1 (or equiv.) indicating we received something.
1100 static void fc_seq_send_ack(struct fc_seq *sp, const struct fc_frame *rx_fp)
1102 struct fc_frame *fp;
1103 struct fc_frame_header *rx_fh;
1104 struct fc_frame_header *fh;
1105 struct fc_exch *ep = fc_seq_exch(sp);
1106 struct fc_lport *lport = ep->lp;
1107 unsigned int f_ctl;
1110 * Don't send ACKs for class 3.
1112 if (fc_sof_needs_ack(fr_sof(rx_fp))) {
1113 fp = fc_frame_alloc(lport, 0);
1114 if (!fp)
1115 return;
1117 fh = fc_frame_header_get(fp);
1118 fh->fh_r_ctl = FC_RCTL_ACK_1;
1119 fh->fh_type = FC_TYPE_BLS;
1122 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1123 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1124 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1125 * Last ACK uses bits 7-6 (continue sequence),
1126 * bits 5-4 are meaningful (what kind of ACK to use).
1128 rx_fh = fc_frame_header_get(rx_fp);
1129 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1130 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1131 FC_FC_FIRST_SEQ | FC_FC_LAST_SEQ |
1132 FC_FC_END_SEQ | FC_FC_END_CONN | FC_FC_SEQ_INIT |
1133 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1134 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1135 hton24(fh->fh_f_ctl, f_ctl);
1137 fc_exch_setup_hdr(ep, fp, f_ctl);
1138 fh->fh_seq_id = rx_fh->fh_seq_id;
1139 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1140 fh->fh_parm_offset = htonl(1); /* ack single frame */
1142 fr_sof(fp) = fr_sof(rx_fp);
1143 if (f_ctl & FC_FC_END_SEQ)
1144 fr_eof(fp) = FC_EOF_T;
1145 else
1146 fr_eof(fp) = FC_EOF_N;
1148 lport->tt.frame_send(lport, fp);
1153 * fc_exch_send_ba_rjt() - Send BLS Reject
1154 * @rx_fp: The frame being rejected
1155 * @reason: The reason the frame is being rejected
1156 * @explan: The explanation for the rejection
1158 * This is for rejecting BA_ABTS only.
1160 static void fc_exch_send_ba_rjt(struct fc_frame *rx_fp,
1161 enum fc_ba_rjt_reason reason,
1162 enum fc_ba_rjt_explan explan)
1164 struct fc_frame *fp;
1165 struct fc_frame_header *rx_fh;
1166 struct fc_frame_header *fh;
1167 struct fc_ba_rjt *rp;
1168 struct fc_lport *lport;
1169 unsigned int f_ctl;
1171 lport = fr_dev(rx_fp);
1172 fp = fc_frame_alloc(lport, sizeof(*rp));
1173 if (!fp)
1174 return;
1175 fh = fc_frame_header_get(fp);
1176 rx_fh = fc_frame_header_get(rx_fp);
1178 memset(fh, 0, sizeof(*fh) + sizeof(*rp));
1180 rp = fc_frame_payload_get(fp, sizeof(*rp));
1181 rp->br_reason = reason;
1182 rp->br_explan = explan;
1185 * seq_id, cs_ctl, df_ctl and param/offset are zero.
1187 memcpy(fh->fh_s_id, rx_fh->fh_d_id, 3);
1188 memcpy(fh->fh_d_id, rx_fh->fh_s_id, 3);
1189 fh->fh_ox_id = rx_fh->fh_ox_id;
1190 fh->fh_rx_id = rx_fh->fh_rx_id;
1191 fh->fh_seq_cnt = rx_fh->fh_seq_cnt;
1192 fh->fh_r_ctl = FC_RCTL_BA_RJT;
1193 fh->fh_type = FC_TYPE_BLS;
1196 * Form f_ctl by inverting EX_CTX and SEQ_CTX (bits 23, 22).
1197 * Echo FIRST_SEQ, LAST_SEQ, END_SEQ, END_CONN, SEQ_INIT.
1198 * Bits 9-8 are meaningful (retransmitted or unidirectional).
1199 * Last ACK uses bits 7-6 (continue sequence),
1200 * bits 5-4 are meaningful (what kind of ACK to use).
1201 * Always set LAST_SEQ, END_SEQ.
1203 f_ctl = ntoh24(rx_fh->fh_f_ctl);
1204 f_ctl &= FC_FC_EX_CTX | FC_FC_SEQ_CTX |
1205 FC_FC_END_CONN | FC_FC_SEQ_INIT |
1206 FC_FC_RETX_SEQ | FC_FC_UNI_TX;
1207 f_ctl ^= FC_FC_EX_CTX | FC_FC_SEQ_CTX;
1208 f_ctl |= FC_FC_LAST_SEQ | FC_FC_END_SEQ;
1209 f_ctl &= ~FC_FC_FIRST_SEQ;
1210 hton24(fh->fh_f_ctl, f_ctl);
1212 fr_sof(fp) = fc_sof_class(fr_sof(rx_fp));
1213 fr_eof(fp) = FC_EOF_T;
1214 if (fc_sof_needs_ack(fr_sof(fp)))
1215 fr_eof(fp) = FC_EOF_N;
1217 lport->tt.frame_send(lport, fp);
1221 * fc_exch_recv_abts() - Handle an incoming ABTS
1222 * @ep: The exchange the abort was on
1223 * @rx_fp: The ABTS frame
1225 * This would be for target mode usually, but could be due to lost
1226 * FCP transfer ready, confirm or RRQ. We always handle this as an
1227 * exchange abort, ignoring the parameter.
1229 static void fc_exch_recv_abts(struct fc_exch *ep, struct fc_frame *rx_fp)
1231 struct fc_frame *fp;
1232 struct fc_ba_acc *ap;
1233 struct fc_frame_header *fh;
1234 struct fc_seq *sp;
1236 if (!ep)
1237 goto reject;
1238 spin_lock_bh(&ep->ex_lock);
1239 if (ep->esb_stat & ESB_ST_COMPLETE) {
1240 spin_unlock_bh(&ep->ex_lock);
1241 goto reject;
1243 if (!(ep->esb_stat & ESB_ST_REC_QUAL))
1244 fc_exch_hold(ep); /* hold for REC_QUAL */
1245 ep->esb_stat |= ESB_ST_ABNORMAL | ESB_ST_REC_QUAL;
1246 fc_exch_timer_set_locked(ep, ep->r_a_tov);
1248 fp = fc_frame_alloc(ep->lp, sizeof(*ap));
1249 if (!fp) {
1250 spin_unlock_bh(&ep->ex_lock);
1251 goto free;
1253 fh = fc_frame_header_get(fp);
1254 ap = fc_frame_payload_get(fp, sizeof(*ap));
1255 memset(ap, 0, sizeof(*ap));
1256 sp = &ep->seq;
1257 ap->ba_high_seq_cnt = htons(0xffff);
1258 if (sp->ssb_stat & SSB_ST_RESP) {
1259 ap->ba_seq_id = sp->id;
1260 ap->ba_seq_id_val = FC_BA_SEQ_ID_VAL;
1261 ap->ba_high_seq_cnt = fh->fh_seq_cnt;
1262 ap->ba_low_seq_cnt = htons(sp->cnt);
1264 sp = fc_seq_start_next_locked(sp);
1265 spin_unlock_bh(&ep->ex_lock);
1266 fc_seq_send_last(sp, fp, FC_RCTL_BA_ACC, FC_TYPE_BLS);
1267 fc_frame_free(rx_fp);
1268 return;
1270 reject:
1271 fc_exch_send_ba_rjt(rx_fp, FC_BA_RJT_UNABLE, FC_BA_RJT_INV_XID);
1272 free:
1273 fc_frame_free(rx_fp);
1277 * fc_seq_assign() - Assign exchange and sequence for incoming request
1278 * @lport: The local port that received the request
1279 * @fp: The request frame
1281 * On success, the sequence pointer will be returned and also in fr_seq(@fp).
1282 * A reference will be held on the exchange/sequence for the caller, which
1283 * must call fc_seq_release().
1285 static struct fc_seq *fc_seq_assign(struct fc_lport *lport, struct fc_frame *fp)
1287 struct fc_exch_mgr_anchor *ema;
1289 WARN_ON(lport != fr_dev(fp));
1290 WARN_ON(fr_seq(fp));
1291 fr_seq(fp) = NULL;
1293 list_for_each_entry(ema, &lport->ema_list, ema_list)
1294 if ((!ema->match || ema->match(fp)) &&
1295 fc_seq_lookup_recip(lport, ema->mp, fp) == FC_RJT_NONE)
1296 break;
1297 return fr_seq(fp);
1301 * fc_seq_release() - Release the hold
1302 * @sp: The sequence.
1304 static void fc_seq_release(struct fc_seq *sp)
1306 fc_exch_release(fc_seq_exch(sp));
1310 * fc_exch_recv_req() - Handler for an incoming request
1311 * @lport: The local port that received the request
1312 * @mp: The EM that the exchange is on
1313 * @fp: The request frame
1315 * This is used when the other end is originating the exchange
1316 * and the sequence.
1318 static void fc_exch_recv_req(struct fc_lport *lport, struct fc_exch_mgr *mp,
1319 struct fc_frame *fp)
1321 struct fc_frame_header *fh = fc_frame_header_get(fp);
1322 struct fc_seq *sp = NULL;
1323 struct fc_exch *ep = NULL;
1324 enum fc_pf_rjt_reason reject;
1326 /* We can have the wrong fc_lport at this point with NPIV, which is a
1327 * problem now that we know a new exchange needs to be allocated
1329 lport = fc_vport_id_lookup(lport, ntoh24(fh->fh_d_id));
1330 if (!lport) {
1331 fc_frame_free(fp);
1332 return;
1334 fr_dev(fp) = lport;
1336 BUG_ON(fr_seq(fp)); /* XXX remove later */
1339 * If the RX_ID is 0xffff, don't allocate an exchange.
1340 * The upper-level protocol may request one later, if needed.
1342 if (fh->fh_rx_id == htons(FC_XID_UNKNOWN))
1343 return lport->tt.lport_recv(lport, fp);
1345 reject = fc_seq_lookup_recip(lport, mp, fp);
1346 if (reject == FC_RJT_NONE) {
1347 sp = fr_seq(fp); /* sequence will be held */
1348 ep = fc_seq_exch(sp);
1349 fc_seq_send_ack(sp, fp);
1350 ep->encaps = fr_encaps(fp);
1353 * Call the receive function.
1355 * The receive function may allocate a new sequence
1356 * over the old one, so we shouldn't change the
1357 * sequence after this.
1359 * The frame will be freed by the receive function.
1360 * If new exch resp handler is valid then call that
1361 * first.
1363 if (ep->resp)
1364 ep->resp(sp, fp, ep->arg);
1365 else
1366 lport->tt.lport_recv(lport, fp);
1367 fc_exch_release(ep); /* release from lookup */
1368 } else {
1369 FC_LPORT_DBG(lport, "exch/seq lookup failed: reject %x\n",
1370 reject);
1371 fc_frame_free(fp);
1376 * fc_exch_recv_seq_resp() - Handler for an incoming response where the other
1377 * end is the originator of the sequence that is a
1378 * response to our initial exchange
1379 * @mp: The EM that the exchange is on
1380 * @fp: The response frame
1382 static void fc_exch_recv_seq_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1384 struct fc_frame_header *fh = fc_frame_header_get(fp);
1385 struct fc_seq *sp;
1386 struct fc_exch *ep;
1387 enum fc_sof sof;
1388 u32 f_ctl;
1389 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
1390 void *ex_resp_arg;
1391 int rc;
1393 ep = fc_exch_find(mp, ntohs(fh->fh_ox_id));
1394 if (!ep) {
1395 atomic_inc(&mp->stats.xid_not_found);
1396 goto out;
1398 if (ep->esb_stat & ESB_ST_COMPLETE) {
1399 atomic_inc(&mp->stats.xid_not_found);
1400 goto rel;
1402 if (ep->rxid == FC_XID_UNKNOWN)
1403 ep->rxid = ntohs(fh->fh_rx_id);
1404 if (ep->sid != 0 && ep->sid != ntoh24(fh->fh_d_id)) {
1405 atomic_inc(&mp->stats.xid_not_found);
1406 goto rel;
1408 if (ep->did != ntoh24(fh->fh_s_id) &&
1409 ep->did != FC_FID_FLOGI) {
1410 atomic_inc(&mp->stats.xid_not_found);
1411 goto rel;
1413 sof = fr_sof(fp);
1414 sp = &ep->seq;
1415 if (fc_sof_is_init(sof)) {
1416 sp->ssb_stat |= SSB_ST_RESP;
1417 sp->id = fh->fh_seq_id;
1418 } else if (sp->id != fh->fh_seq_id) {
1419 atomic_inc(&mp->stats.seq_not_found);
1420 goto rel;
1423 f_ctl = ntoh24(fh->fh_f_ctl);
1424 fr_seq(fp) = sp;
1425 if (f_ctl & FC_FC_SEQ_INIT)
1426 ep->esb_stat |= ESB_ST_SEQ_INIT;
1428 if (fc_sof_needs_ack(sof))
1429 fc_seq_send_ack(sp, fp);
1430 resp = ep->resp;
1431 ex_resp_arg = ep->arg;
1433 if (fh->fh_type != FC_TYPE_FCP && fr_eof(fp) == FC_EOF_T &&
1434 (f_ctl & (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) ==
1435 (FC_FC_LAST_SEQ | FC_FC_END_SEQ)) {
1436 spin_lock_bh(&ep->ex_lock);
1437 rc = fc_exch_done_locked(ep);
1438 WARN_ON(fc_seq_exch(sp) != ep);
1439 spin_unlock_bh(&ep->ex_lock);
1440 if (!rc)
1441 fc_exch_delete(ep);
1445 * Call the receive function.
1446 * The sequence is held (has a refcnt) for us,
1447 * but not for the receive function.
1449 * The receive function may allocate a new sequence
1450 * over the old one, so we shouldn't change the
1451 * sequence after this.
1453 * The frame will be freed by the receive function.
1454 * If new exch resp handler is valid then call that
1455 * first.
1457 if (resp)
1458 resp(sp, fp, ex_resp_arg);
1459 else
1460 fc_frame_free(fp);
1461 fc_exch_release(ep);
1462 return;
1463 rel:
1464 fc_exch_release(ep);
1465 out:
1466 fc_frame_free(fp);
1470 * fc_exch_recv_resp() - Handler for a sequence where other end is
1471 * responding to our sequence
1472 * @mp: The EM that the exchange is on
1473 * @fp: The response frame
1475 static void fc_exch_recv_resp(struct fc_exch_mgr *mp, struct fc_frame *fp)
1477 struct fc_seq *sp;
1479 sp = fc_seq_lookup_orig(mp, fp); /* doesn't hold sequence */
1481 if (!sp)
1482 atomic_inc(&mp->stats.xid_not_found);
1483 else
1484 atomic_inc(&mp->stats.non_bls_resp);
1486 fc_frame_free(fp);
1490 * fc_exch_abts_resp() - Handler for a response to an ABT
1491 * @ep: The exchange that the frame is on
1492 * @fp: The response frame
1494 * This response would be to an ABTS cancelling an exchange or sequence.
1495 * The response can be either BA_ACC or BA_RJT
1497 static void fc_exch_abts_resp(struct fc_exch *ep, struct fc_frame *fp)
1499 void (*resp)(struct fc_seq *, struct fc_frame *fp, void *arg);
1500 void *ex_resp_arg;
1501 struct fc_frame_header *fh;
1502 struct fc_ba_acc *ap;
1503 struct fc_seq *sp;
1504 u16 low;
1505 u16 high;
1506 int rc = 1, has_rec = 0;
1508 fh = fc_frame_header_get(fp);
1509 FC_EXCH_DBG(ep, "exch: BLS rctl %x - %s\n", fh->fh_r_ctl,
1510 fc_exch_rctl_name(fh->fh_r_ctl));
1512 if (cancel_delayed_work_sync(&ep->timeout_work))
1513 fc_exch_release(ep); /* release from pending timer hold */
1515 spin_lock_bh(&ep->ex_lock);
1516 switch (fh->fh_r_ctl) {
1517 case FC_RCTL_BA_ACC:
1518 ap = fc_frame_payload_get(fp, sizeof(*ap));
1519 if (!ap)
1520 break;
1523 * Decide whether to establish a Recovery Qualifier.
1524 * We do this if there is a non-empty SEQ_CNT range and
1525 * SEQ_ID is the same as the one we aborted.
1527 low = ntohs(ap->ba_low_seq_cnt);
1528 high = ntohs(ap->ba_high_seq_cnt);
1529 if ((ep->esb_stat & ESB_ST_REC_QUAL) == 0 &&
1530 (ap->ba_seq_id_val != FC_BA_SEQ_ID_VAL ||
1531 ap->ba_seq_id == ep->seq_id) && low != high) {
1532 ep->esb_stat |= ESB_ST_REC_QUAL;
1533 fc_exch_hold(ep); /* hold for recovery qualifier */
1534 has_rec = 1;
1536 break;
1537 case FC_RCTL_BA_RJT:
1538 break;
1539 default:
1540 break;
1543 resp = ep->resp;
1544 ex_resp_arg = ep->arg;
1546 /* do we need to do some other checks here. Can we reuse more of
1547 * fc_exch_recv_seq_resp
1549 sp = &ep->seq;
1551 * do we want to check END_SEQ as well as LAST_SEQ here?
1553 if (ep->fh_type != FC_TYPE_FCP &&
1554 ntoh24(fh->fh_f_ctl) & FC_FC_LAST_SEQ)
1555 rc = fc_exch_done_locked(ep);
1556 spin_unlock_bh(&ep->ex_lock);
1557 if (!rc)
1558 fc_exch_delete(ep);
1560 if (resp)
1561 resp(sp, fp, ex_resp_arg);
1562 else
1563 fc_frame_free(fp);
1565 if (has_rec)
1566 fc_exch_timer_set(ep, ep->r_a_tov);
1571 * fc_exch_recv_bls() - Handler for a BLS sequence
1572 * @mp: The EM that the exchange is on
1573 * @fp: The request frame
1575 * The BLS frame is always a sequence initiated by the remote side.
1576 * We may be either the originator or recipient of the exchange.
1578 static void fc_exch_recv_bls(struct fc_exch_mgr *mp, struct fc_frame *fp)
1580 struct fc_frame_header *fh;
1581 struct fc_exch *ep;
1582 u32 f_ctl;
1584 fh = fc_frame_header_get(fp);
1585 f_ctl = ntoh24(fh->fh_f_ctl);
1586 fr_seq(fp) = NULL;
1588 ep = fc_exch_find(mp, (f_ctl & FC_FC_EX_CTX) ?
1589 ntohs(fh->fh_ox_id) : ntohs(fh->fh_rx_id));
1590 if (ep && (f_ctl & FC_FC_SEQ_INIT)) {
1591 spin_lock_bh(&ep->ex_lock);
1592 ep->esb_stat |= ESB_ST_SEQ_INIT;
1593 spin_unlock_bh(&ep->ex_lock);
1595 if (f_ctl & FC_FC_SEQ_CTX) {
1597 * A response to a sequence we initiated.
1598 * This should only be ACKs for class 2 or F.
1600 switch (fh->fh_r_ctl) {
1601 case FC_RCTL_ACK_1:
1602 case FC_RCTL_ACK_0:
1603 break;
1604 default:
1605 FC_EXCH_DBG(ep, "BLS rctl %x - %s received",
1606 fh->fh_r_ctl,
1607 fc_exch_rctl_name(fh->fh_r_ctl));
1608 break;
1610 fc_frame_free(fp);
1611 } else {
1612 switch (fh->fh_r_ctl) {
1613 case FC_RCTL_BA_RJT:
1614 case FC_RCTL_BA_ACC:
1615 if (ep)
1616 fc_exch_abts_resp(ep, fp);
1617 else
1618 fc_frame_free(fp);
1619 break;
1620 case FC_RCTL_BA_ABTS:
1621 fc_exch_recv_abts(ep, fp);
1622 break;
1623 default: /* ignore junk */
1624 fc_frame_free(fp);
1625 break;
1628 if (ep)
1629 fc_exch_release(ep); /* release hold taken by fc_exch_find */
1633 * fc_seq_ls_acc() - Accept sequence with LS_ACC
1634 * @rx_fp: The received frame, not freed here.
1636 * If this fails due to allocation or transmit congestion, assume the
1637 * originator will repeat the sequence.
1639 static void fc_seq_ls_acc(struct fc_frame *rx_fp)
1641 struct fc_lport *lport;
1642 struct fc_els_ls_acc *acc;
1643 struct fc_frame *fp;
1645 lport = fr_dev(rx_fp);
1646 fp = fc_frame_alloc(lport, sizeof(*acc));
1647 if (!fp)
1648 return;
1649 acc = fc_frame_payload_get(fp, sizeof(*acc));
1650 memset(acc, 0, sizeof(*acc));
1651 acc->la_cmd = ELS_LS_ACC;
1652 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1653 lport->tt.frame_send(lport, fp);
1657 * fc_seq_ls_rjt() - Reject a sequence with ELS LS_RJT
1658 * @rx_fp: The received frame, not freed here.
1659 * @reason: The reason the sequence is being rejected
1660 * @explan: The explanation for the rejection
1662 * If this fails due to allocation or transmit congestion, assume the
1663 * originator will repeat the sequence.
1665 static void fc_seq_ls_rjt(struct fc_frame *rx_fp, enum fc_els_rjt_reason reason,
1666 enum fc_els_rjt_explan explan)
1668 struct fc_lport *lport;
1669 struct fc_els_ls_rjt *rjt;
1670 struct fc_frame *fp;
1672 lport = fr_dev(rx_fp);
1673 fp = fc_frame_alloc(lport, sizeof(*rjt));
1674 if (!fp)
1675 return;
1676 rjt = fc_frame_payload_get(fp, sizeof(*rjt));
1677 memset(rjt, 0, sizeof(*rjt));
1678 rjt->er_cmd = ELS_LS_RJT;
1679 rjt->er_reason = reason;
1680 rjt->er_explan = explan;
1681 fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_ELS_REP, 0);
1682 lport->tt.frame_send(lport, fp);
1686 * fc_exch_reset() - Reset an exchange
1687 * @ep: The exchange to be reset
1689 static void fc_exch_reset(struct fc_exch *ep)
1691 struct fc_seq *sp;
1692 void (*resp)(struct fc_seq *, struct fc_frame *, void *);
1693 void *arg;
1694 int rc = 1;
1696 spin_lock_bh(&ep->ex_lock);
1697 ep->state |= FC_EX_RST_CLEANUP;
1698 if (cancel_delayed_work(&ep->timeout_work))
1699 atomic_dec(&ep->ex_refcnt); /* drop hold for timer */
1700 resp = ep->resp;
1701 ep->resp = NULL;
1702 if (ep->esb_stat & ESB_ST_REC_QUAL)
1703 atomic_dec(&ep->ex_refcnt); /* drop hold for rec_qual */
1704 ep->esb_stat &= ~ESB_ST_REC_QUAL;
1705 arg = ep->arg;
1706 sp = &ep->seq;
1707 rc = fc_exch_done_locked(ep);
1708 spin_unlock_bh(&ep->ex_lock);
1709 if (!rc)
1710 fc_exch_delete(ep);
1712 if (resp)
1713 resp(sp, ERR_PTR(-FC_EX_CLOSED), arg);
1717 * fc_exch_pool_reset() - Reset a per cpu exchange pool
1718 * @lport: The local port that the exchange pool is on
1719 * @pool: The exchange pool to be reset
1720 * @sid: The source ID
1721 * @did: The destination ID
1723 * Resets a per cpu exches pool, releasing all of its sequences
1724 * and exchanges. If sid is non-zero then reset only exchanges
1725 * we sourced from the local port's FID. If did is non-zero then
1726 * only reset exchanges destined for the local port's FID.
1728 static void fc_exch_pool_reset(struct fc_lport *lport,
1729 struct fc_exch_pool *pool,
1730 u32 sid, u32 did)
1732 struct fc_exch *ep;
1733 struct fc_exch *next;
1735 spin_lock_bh(&pool->lock);
1736 restart:
1737 list_for_each_entry_safe(ep, next, &pool->ex_list, ex_list) {
1738 if ((lport == ep->lp) &&
1739 (sid == 0 || sid == ep->sid) &&
1740 (did == 0 || did == ep->did)) {
1741 fc_exch_hold(ep);
1742 spin_unlock_bh(&pool->lock);
1744 fc_exch_reset(ep);
1746 fc_exch_release(ep);
1747 spin_lock_bh(&pool->lock);
1750 * must restart loop incase while lock
1751 * was down multiple eps were released.
1753 goto restart;
1756 spin_unlock_bh(&pool->lock);
1760 * fc_exch_mgr_reset() - Reset all EMs of a local port
1761 * @lport: The local port whose EMs are to be reset
1762 * @sid: The source ID
1763 * @did: The destination ID
1765 * Reset all EMs associated with a given local port. Release all
1766 * sequences and exchanges. If sid is non-zero then reset only the
1767 * exchanges sent from the local port's FID. If did is non-zero then
1768 * reset only exchanges destined for the local port's FID.
1770 void fc_exch_mgr_reset(struct fc_lport *lport, u32 sid, u32 did)
1772 struct fc_exch_mgr_anchor *ema;
1773 unsigned int cpu;
1775 list_for_each_entry(ema, &lport->ema_list, ema_list) {
1776 for_each_possible_cpu(cpu)
1777 fc_exch_pool_reset(lport,
1778 per_cpu_ptr(ema->mp->pool, cpu),
1779 sid, did);
1782 EXPORT_SYMBOL(fc_exch_mgr_reset);
1785 * fc_exch_lookup() - find an exchange
1786 * @lport: The local port
1787 * @xid: The exchange ID
1789 * Returns exchange pointer with hold for caller, or NULL if not found.
1791 static struct fc_exch *fc_exch_lookup(struct fc_lport *lport, u32 xid)
1793 struct fc_exch_mgr_anchor *ema;
1795 list_for_each_entry(ema, &lport->ema_list, ema_list)
1796 if (ema->mp->min_xid <= xid && xid <= ema->mp->max_xid)
1797 return fc_exch_find(ema->mp, xid);
1798 return NULL;
1802 * fc_exch_els_rec() - Handler for ELS REC (Read Exchange Concise) requests
1803 * @rfp: The REC frame, not freed here.
1805 * Note that the requesting port may be different than the S_ID in the request.
1807 static void fc_exch_els_rec(struct fc_frame *rfp)
1809 struct fc_lport *lport;
1810 struct fc_frame *fp;
1811 struct fc_exch *ep;
1812 struct fc_els_rec *rp;
1813 struct fc_els_rec_acc *acc;
1814 enum fc_els_rjt_reason reason = ELS_RJT_LOGIC;
1815 enum fc_els_rjt_explan explan;
1816 u32 sid;
1817 u16 rxid;
1818 u16 oxid;
1820 lport = fr_dev(rfp);
1821 rp = fc_frame_payload_get(rfp, sizeof(*rp));
1822 explan = ELS_EXPL_INV_LEN;
1823 if (!rp)
1824 goto reject;
1825 sid = ntoh24(rp->rec_s_id);
1826 rxid = ntohs(rp->rec_rx_id);
1827 oxid = ntohs(rp->rec_ox_id);
1829 ep = fc_exch_lookup(lport,
1830 sid == fc_host_port_id(lport->host) ? oxid : rxid);
1831 explan = ELS_EXPL_OXID_RXID;
1832 if (!ep)
1833 goto reject;
1834 if (ep->oid != sid || oxid != ep->oxid)
1835 goto rel;
1836 if (rxid != FC_XID_UNKNOWN && rxid != ep->rxid)
1837 goto rel;
1838 fp = fc_frame_alloc(lport, sizeof(*acc));
1839 if (!fp)
1840 goto out;
1842 acc = fc_frame_payload_get(fp, sizeof(*acc));
1843 memset(acc, 0, sizeof(*acc));
1844 acc->reca_cmd = ELS_LS_ACC;
1845 acc->reca_ox_id = rp->rec_ox_id;
1846 memcpy(acc->reca_ofid, rp->rec_s_id, 3);
1847 acc->reca_rx_id = htons(ep->rxid);
1848 if (ep->sid == ep->oid)
1849 hton24(acc->reca_rfid, ep->did);
1850 else
1851 hton24(acc->reca_rfid, ep->sid);
1852 acc->reca_fc4value = htonl(ep->seq.rec_data);
1853 acc->reca_e_stat = htonl(ep->esb_stat & (ESB_ST_RESP |
1854 ESB_ST_SEQ_INIT |
1855 ESB_ST_COMPLETE));
1856 fc_fill_reply_hdr(fp, rfp, FC_RCTL_ELS_REP, 0);
1857 lport->tt.frame_send(lport, fp);
1858 out:
1859 fc_exch_release(ep);
1860 return;
1862 rel:
1863 fc_exch_release(ep);
1864 reject:
1865 fc_seq_ls_rjt(rfp, reason, explan);
1869 * fc_exch_rrq_resp() - Handler for RRQ responses
1870 * @sp: The sequence that the RRQ is on
1871 * @fp: The RRQ frame
1872 * @arg: The exchange that the RRQ is on
1874 * TODO: fix error handler.
1876 static void fc_exch_rrq_resp(struct fc_seq *sp, struct fc_frame *fp, void *arg)
1878 struct fc_exch *aborted_ep = arg;
1879 unsigned int op;
1881 if (IS_ERR(fp)) {
1882 int err = PTR_ERR(fp);
1884 if (err == -FC_EX_CLOSED || err == -FC_EX_TIMEOUT)
1885 goto cleanup;
1886 FC_EXCH_DBG(aborted_ep, "Cannot process RRQ, "
1887 "frame error %d\n", err);
1888 return;
1891 op = fc_frame_payload_op(fp);
1892 fc_frame_free(fp);
1894 switch (op) {
1895 case ELS_LS_RJT:
1896 FC_EXCH_DBG(aborted_ep, "LS_RJT for RRQ");
1897 /* fall through */
1898 case ELS_LS_ACC:
1899 goto cleanup;
1900 default:
1901 FC_EXCH_DBG(aborted_ep, "unexpected response op %x "
1902 "for RRQ", op);
1903 return;
1906 cleanup:
1907 fc_exch_done(&aborted_ep->seq);
1908 /* drop hold for rec qual */
1909 fc_exch_release(aborted_ep);
1914 * fc_exch_seq_send() - Send a frame using a new exchange and sequence
1915 * @lport: The local port to send the frame on
1916 * @fp: The frame to be sent
1917 * @resp: The response handler for this request
1918 * @destructor: The destructor for the exchange
1919 * @arg: The argument to be passed to the response handler
1920 * @timer_msec: The timeout period for the exchange
1922 * The frame pointer with some of the header's fields must be
1923 * filled before calling this routine, those fields are:
1925 * - routing control
1926 * - FC port did
1927 * - FC port sid
1928 * - FC header type
1929 * - frame control
1930 * - parameter or relative offset
1932 static struct fc_seq *fc_exch_seq_send(struct fc_lport *lport,
1933 struct fc_frame *fp,
1934 void (*resp)(struct fc_seq *,
1935 struct fc_frame *fp,
1936 void *arg),
1937 void (*destructor)(struct fc_seq *,
1938 void *),
1939 void *arg, u32 timer_msec)
1941 struct fc_exch *ep;
1942 struct fc_seq *sp = NULL;
1943 struct fc_frame_header *fh;
1944 int rc = 1;
1946 ep = fc_exch_alloc(lport, fp);
1947 if (!ep) {
1948 fc_frame_free(fp);
1949 return NULL;
1951 ep->esb_stat |= ESB_ST_SEQ_INIT;
1952 fh = fc_frame_header_get(fp);
1953 fc_exch_set_addr(ep, ntoh24(fh->fh_s_id), ntoh24(fh->fh_d_id));
1954 ep->resp = resp;
1955 ep->destructor = destructor;
1956 ep->arg = arg;
1957 ep->r_a_tov = FC_DEF_R_A_TOV;
1958 ep->lp = lport;
1959 sp = &ep->seq;
1961 ep->fh_type = fh->fh_type; /* save for possbile timeout handling */
1962 ep->f_ctl = ntoh24(fh->fh_f_ctl);
1963 fc_exch_setup_hdr(ep, fp, ep->f_ctl);
1964 sp->cnt++;
1966 if (ep->xid <= lport->lro_xid && fh->fh_r_ctl == FC_RCTL_DD_UNSOL_CMD)
1967 fc_fcp_ddp_setup(fr_fsp(fp), ep->xid);
1969 if (unlikely(lport->tt.frame_send(lport, fp)))
1970 goto err;
1972 if (timer_msec)
1973 fc_exch_timer_set_locked(ep, timer_msec);
1974 ep->f_ctl &= ~FC_FC_FIRST_SEQ; /* not first seq */
1976 if (ep->f_ctl & FC_FC_SEQ_INIT)
1977 ep->esb_stat &= ~ESB_ST_SEQ_INIT;
1978 spin_unlock_bh(&ep->ex_lock);
1979 return sp;
1980 err:
1981 rc = fc_exch_done_locked(ep);
1982 spin_unlock_bh(&ep->ex_lock);
1983 if (!rc)
1984 fc_exch_delete(ep);
1985 return NULL;
1989 * fc_exch_rrq() - Send an ELS RRQ (Reinstate Recovery Qualifier) command
1990 * @ep: The exchange to send the RRQ on
1992 * This tells the remote port to stop blocking the use of
1993 * the exchange and the seq_cnt range.
1995 static void fc_exch_rrq(struct fc_exch *ep)
1997 struct fc_lport *lport;
1998 struct fc_els_rrq *rrq;
1999 struct fc_frame *fp;
2000 u32 did;
2002 lport = ep->lp;
2004 fp = fc_frame_alloc(lport, sizeof(*rrq));
2005 if (!fp)
2006 goto retry;
2008 rrq = fc_frame_payload_get(fp, sizeof(*rrq));
2009 memset(rrq, 0, sizeof(*rrq));
2010 rrq->rrq_cmd = ELS_RRQ;
2011 hton24(rrq->rrq_s_id, ep->sid);
2012 rrq->rrq_ox_id = htons(ep->oxid);
2013 rrq->rrq_rx_id = htons(ep->rxid);
2015 did = ep->did;
2016 if (ep->esb_stat & ESB_ST_RESP)
2017 did = ep->sid;
2019 fc_fill_fc_hdr(fp, FC_RCTL_ELS_REQ, did,
2020 lport->port_id, FC_TYPE_ELS,
2021 FC_FC_FIRST_SEQ | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
2023 if (fc_exch_seq_send(lport, fp, fc_exch_rrq_resp, NULL, ep,
2024 lport->e_d_tov))
2025 return;
2027 retry:
2028 spin_lock_bh(&ep->ex_lock);
2029 if (ep->state & (FC_EX_RST_CLEANUP | FC_EX_DONE)) {
2030 spin_unlock_bh(&ep->ex_lock);
2031 /* drop hold for rec qual */
2032 fc_exch_release(ep);
2033 return;
2035 ep->esb_stat |= ESB_ST_REC_QUAL;
2036 fc_exch_timer_set_locked(ep, ep->r_a_tov);
2037 spin_unlock_bh(&ep->ex_lock);
2041 * fc_exch_els_rrq() - Handler for ELS RRQ (Reset Recovery Qualifier) requests
2042 * @fp: The RRQ frame, not freed here.
2044 static void fc_exch_els_rrq(struct fc_frame *fp)
2046 struct fc_lport *lport;
2047 struct fc_exch *ep = NULL; /* request or subject exchange */
2048 struct fc_els_rrq *rp;
2049 u32 sid;
2050 u16 xid;
2051 enum fc_els_rjt_explan explan;
2053 lport = fr_dev(fp);
2054 rp = fc_frame_payload_get(fp, sizeof(*rp));
2055 explan = ELS_EXPL_INV_LEN;
2056 if (!rp)
2057 goto reject;
2060 * lookup subject exchange.
2062 sid = ntoh24(rp->rrq_s_id); /* subject source */
2063 xid = fc_host_port_id(lport->host) == sid ?
2064 ntohs(rp->rrq_ox_id) : ntohs(rp->rrq_rx_id);
2065 ep = fc_exch_lookup(lport, xid);
2066 explan = ELS_EXPL_OXID_RXID;
2067 if (!ep)
2068 goto reject;
2069 spin_lock_bh(&ep->ex_lock);
2070 if (ep->oxid != ntohs(rp->rrq_ox_id))
2071 goto unlock_reject;
2072 if (ep->rxid != ntohs(rp->rrq_rx_id) &&
2073 ep->rxid != FC_XID_UNKNOWN)
2074 goto unlock_reject;
2075 explan = ELS_EXPL_SID;
2076 if (ep->sid != sid)
2077 goto unlock_reject;
2080 * Clear Recovery Qualifier state, and cancel timer if complete.
2082 if (ep->esb_stat & ESB_ST_REC_QUAL) {
2083 ep->esb_stat &= ~ESB_ST_REC_QUAL;
2084 atomic_dec(&ep->ex_refcnt); /* drop hold for rec qual */
2086 if (ep->esb_stat & ESB_ST_COMPLETE) {
2087 if (cancel_delayed_work(&ep->timeout_work))
2088 atomic_dec(&ep->ex_refcnt); /* drop timer hold */
2091 spin_unlock_bh(&ep->ex_lock);
2094 * Send LS_ACC.
2096 fc_seq_ls_acc(fp);
2097 goto out;
2099 unlock_reject:
2100 spin_unlock_bh(&ep->ex_lock);
2101 reject:
2102 fc_seq_ls_rjt(fp, ELS_RJT_LOGIC, explan);
2103 out:
2104 if (ep)
2105 fc_exch_release(ep); /* drop hold from fc_exch_find */
2109 * fc_exch_mgr_add() - Add an exchange manager to a local port's list of EMs
2110 * @lport: The local port to add the exchange manager to
2111 * @mp: The exchange manager to be added to the local port
2112 * @match: The match routine that indicates when this EM should be used
2114 struct fc_exch_mgr_anchor *fc_exch_mgr_add(struct fc_lport *lport,
2115 struct fc_exch_mgr *mp,
2116 bool (*match)(struct fc_frame *))
2118 struct fc_exch_mgr_anchor *ema;
2120 ema = kmalloc(sizeof(*ema), GFP_ATOMIC);
2121 if (!ema)
2122 return ema;
2124 ema->mp = mp;
2125 ema->match = match;
2126 /* add EM anchor to EM anchors list */
2127 list_add_tail(&ema->ema_list, &lport->ema_list);
2128 kref_get(&mp->kref);
2129 return ema;
2131 EXPORT_SYMBOL(fc_exch_mgr_add);
2134 * fc_exch_mgr_destroy() - Destroy an exchange manager
2135 * @kref: The reference to the EM to be destroyed
2137 static void fc_exch_mgr_destroy(struct kref *kref)
2139 struct fc_exch_mgr *mp = container_of(kref, struct fc_exch_mgr, kref);
2141 mempool_destroy(mp->ep_pool);
2142 free_percpu(mp->pool);
2143 kfree(mp);
2147 * fc_exch_mgr_del() - Delete an EM from a local port's list
2148 * @ema: The exchange manager anchor identifying the EM to be deleted
2150 void fc_exch_mgr_del(struct fc_exch_mgr_anchor *ema)
2152 /* remove EM anchor from EM anchors list */
2153 list_del(&ema->ema_list);
2154 kref_put(&ema->mp->kref, fc_exch_mgr_destroy);
2155 kfree(ema);
2157 EXPORT_SYMBOL(fc_exch_mgr_del);
2160 * fc_exch_mgr_list_clone() - Share all exchange manager objects
2161 * @src: Source lport to clone exchange managers from
2162 * @dst: New lport that takes references to all the exchange managers
2164 int fc_exch_mgr_list_clone(struct fc_lport *src, struct fc_lport *dst)
2166 struct fc_exch_mgr_anchor *ema, *tmp;
2168 list_for_each_entry(ema, &src->ema_list, ema_list) {
2169 if (!fc_exch_mgr_add(dst, ema->mp, ema->match))
2170 goto err;
2172 return 0;
2173 err:
2174 list_for_each_entry_safe(ema, tmp, &dst->ema_list, ema_list)
2175 fc_exch_mgr_del(ema);
2176 return -ENOMEM;
2178 EXPORT_SYMBOL(fc_exch_mgr_list_clone);
2181 * fc_exch_mgr_alloc() - Allocate an exchange manager
2182 * @lport: The local port that the new EM will be associated with
2183 * @class: The default FC class for new exchanges
2184 * @min_xid: The minimum XID for exchanges from the new EM
2185 * @max_xid: The maximum XID for exchanges from the new EM
2186 * @match: The match routine for the new EM
2188 struct fc_exch_mgr *fc_exch_mgr_alloc(struct fc_lport *lport,
2189 enum fc_class class,
2190 u16 min_xid, u16 max_xid,
2191 bool (*match)(struct fc_frame *))
2193 struct fc_exch_mgr *mp;
2194 u16 pool_exch_range;
2195 size_t pool_size;
2196 unsigned int cpu;
2197 struct fc_exch_pool *pool;
2199 if (max_xid <= min_xid || max_xid == FC_XID_UNKNOWN ||
2200 (min_xid & fc_cpu_mask) != 0) {
2201 FC_LPORT_DBG(lport, "Invalid min_xid 0x:%x and max_xid 0x:%x\n",
2202 min_xid, max_xid);
2203 return NULL;
2207 * allocate memory for EM
2209 mp = kzalloc(sizeof(struct fc_exch_mgr), GFP_ATOMIC);
2210 if (!mp)
2211 return NULL;
2213 mp->class = class;
2214 /* adjust em exch xid range for offload */
2215 mp->min_xid = min_xid;
2216 mp->max_xid = max_xid;
2218 mp->ep_pool = mempool_create_slab_pool(2, fc_em_cachep);
2219 if (!mp->ep_pool)
2220 goto free_mp;
2223 * Setup per cpu exch pool with entire exchange id range equally
2224 * divided across all cpus. The exch pointers array memory is
2225 * allocated for exch range per pool.
2227 pool_exch_range = (mp->max_xid - mp->min_xid + 1) / (fc_cpu_mask + 1);
2228 mp->pool_max_index = pool_exch_range - 1;
2231 * Allocate and initialize per cpu exch pool
2233 pool_size = sizeof(*pool) + pool_exch_range * sizeof(struct fc_exch *);
2234 mp->pool = __alloc_percpu(pool_size, __alignof__(struct fc_exch_pool));
2235 if (!mp->pool)
2236 goto free_mempool;
2237 for_each_possible_cpu(cpu) {
2238 pool = per_cpu_ptr(mp->pool, cpu);
2239 pool->left = FC_XID_UNKNOWN;
2240 pool->right = FC_XID_UNKNOWN;
2241 spin_lock_init(&pool->lock);
2242 INIT_LIST_HEAD(&pool->ex_list);
2245 kref_init(&mp->kref);
2246 if (!fc_exch_mgr_add(lport, mp, match)) {
2247 free_percpu(mp->pool);
2248 goto free_mempool;
2252 * Above kref_init() sets mp->kref to 1 and then
2253 * call to fc_exch_mgr_add incremented mp->kref again,
2254 * so adjust that extra increment.
2256 kref_put(&mp->kref, fc_exch_mgr_destroy);
2257 return mp;
2259 free_mempool:
2260 mempool_destroy(mp->ep_pool);
2261 free_mp:
2262 kfree(mp);
2263 return NULL;
2265 EXPORT_SYMBOL(fc_exch_mgr_alloc);
2268 * fc_exch_mgr_free() - Free all exchange managers on a local port
2269 * @lport: The local port whose EMs are to be freed
2271 void fc_exch_mgr_free(struct fc_lport *lport)
2273 struct fc_exch_mgr_anchor *ema, *next;
2275 flush_workqueue(fc_exch_workqueue);
2276 list_for_each_entry_safe(ema, next, &lport->ema_list, ema_list)
2277 fc_exch_mgr_del(ema);
2279 EXPORT_SYMBOL(fc_exch_mgr_free);
2282 * fc_find_ema() - Lookup and return appropriate Exchange Manager Anchor depending
2283 * upon 'xid'.
2284 * @f_ctl: f_ctl
2285 * @lport: The local port the frame was received on
2286 * @fh: The received frame header
2288 static struct fc_exch_mgr_anchor *fc_find_ema(u32 f_ctl,
2289 struct fc_lport *lport,
2290 struct fc_frame_header *fh)
2292 struct fc_exch_mgr_anchor *ema;
2293 u16 xid;
2295 if (f_ctl & FC_FC_EX_CTX)
2296 xid = ntohs(fh->fh_ox_id);
2297 else {
2298 xid = ntohs(fh->fh_rx_id);
2299 if (xid == FC_XID_UNKNOWN)
2300 return list_entry(lport->ema_list.prev,
2301 typeof(*ema), ema_list);
2304 list_for_each_entry(ema, &lport->ema_list, ema_list) {
2305 if ((xid >= ema->mp->min_xid) &&
2306 (xid <= ema->mp->max_xid))
2307 return ema;
2309 return NULL;
2312 * fc_exch_recv() - Handler for received frames
2313 * @lport: The local port the frame was received on
2314 * @fp: The received frame
2316 void fc_exch_recv(struct fc_lport *lport, struct fc_frame *fp)
2318 struct fc_frame_header *fh = fc_frame_header_get(fp);
2319 struct fc_exch_mgr_anchor *ema;
2320 u32 f_ctl;
2322 /* lport lock ? */
2323 if (!lport || lport->state == LPORT_ST_DISABLED) {
2324 FC_LPORT_DBG(lport, "Receiving frames for an lport that "
2325 "has not been initialized correctly\n");
2326 fc_frame_free(fp);
2327 return;
2330 f_ctl = ntoh24(fh->fh_f_ctl);
2331 ema = fc_find_ema(f_ctl, lport, fh);
2332 if (!ema) {
2333 FC_LPORT_DBG(lport, "Unable to find Exchange Manager Anchor,"
2334 "fc_ctl <0x%x>, xid <0x%x>\n",
2335 f_ctl,
2336 (f_ctl & FC_FC_EX_CTX) ?
2337 ntohs(fh->fh_ox_id) :
2338 ntohs(fh->fh_rx_id));
2339 fc_frame_free(fp);
2340 return;
2344 * If frame is marked invalid, just drop it.
2346 switch (fr_eof(fp)) {
2347 case FC_EOF_T:
2348 if (f_ctl & FC_FC_END_SEQ)
2349 skb_trim(fp_skb(fp), fr_len(fp) - FC_FC_FILL(f_ctl));
2350 /* fall through */
2351 case FC_EOF_N:
2352 if (fh->fh_type == FC_TYPE_BLS)
2353 fc_exch_recv_bls(ema->mp, fp);
2354 else if ((f_ctl & (FC_FC_EX_CTX | FC_FC_SEQ_CTX)) ==
2355 FC_FC_EX_CTX)
2356 fc_exch_recv_seq_resp(ema->mp, fp);
2357 else if (f_ctl & FC_FC_SEQ_CTX)
2358 fc_exch_recv_resp(ema->mp, fp);
2359 else /* no EX_CTX and no SEQ_CTX */
2360 fc_exch_recv_req(lport, ema->mp, fp);
2361 break;
2362 default:
2363 FC_LPORT_DBG(lport, "dropping invalid frame (eof %x)",
2364 fr_eof(fp));
2365 fc_frame_free(fp);
2368 EXPORT_SYMBOL(fc_exch_recv);
2371 * fc_exch_init() - Initialize the exchange layer for a local port
2372 * @lport: The local port to initialize the exchange layer for
2374 int fc_exch_init(struct fc_lport *lport)
2376 if (!lport->tt.seq_start_next)
2377 lport->tt.seq_start_next = fc_seq_start_next;
2379 if (!lport->tt.seq_set_resp)
2380 lport->tt.seq_set_resp = fc_seq_set_resp;
2382 if (!lport->tt.exch_seq_send)
2383 lport->tt.exch_seq_send = fc_exch_seq_send;
2385 if (!lport->tt.seq_send)
2386 lport->tt.seq_send = fc_seq_send;
2388 if (!lport->tt.seq_els_rsp_send)
2389 lport->tt.seq_els_rsp_send = fc_seq_els_rsp_send;
2391 if (!lport->tt.exch_done)
2392 lport->tt.exch_done = fc_exch_done;
2394 if (!lport->tt.exch_mgr_reset)
2395 lport->tt.exch_mgr_reset = fc_exch_mgr_reset;
2397 if (!lport->tt.seq_exch_abort)
2398 lport->tt.seq_exch_abort = fc_seq_exch_abort;
2400 if (!lport->tt.seq_assign)
2401 lport->tt.seq_assign = fc_seq_assign;
2403 if (!lport->tt.seq_release)
2404 lport->tt.seq_release = fc_seq_release;
2406 return 0;
2408 EXPORT_SYMBOL(fc_exch_init);
2411 * fc_setup_exch_mgr() - Setup an exchange manager
2413 int fc_setup_exch_mgr(void)
2415 fc_em_cachep = kmem_cache_create("libfc_em", sizeof(struct fc_exch),
2416 0, SLAB_HWCACHE_ALIGN, NULL);
2417 if (!fc_em_cachep)
2418 return -ENOMEM;
2421 * Initialize fc_cpu_mask and fc_cpu_order. The
2422 * fc_cpu_mask is set for nr_cpu_ids rounded up
2423 * to order of 2's * power and order is stored
2424 * in fc_cpu_order as this is later required in
2425 * mapping between an exch id and exch array index
2426 * in per cpu exch pool.
2428 * This round up is required to align fc_cpu_mask
2429 * to exchange id's lower bits such that all incoming
2430 * frames of an exchange gets delivered to the same
2431 * cpu on which exchange originated by simple bitwise
2432 * AND operation between fc_cpu_mask and exchange id.
2434 fc_cpu_mask = 1;
2435 fc_cpu_order = 0;
2436 while (fc_cpu_mask < nr_cpu_ids) {
2437 fc_cpu_mask <<= 1;
2438 fc_cpu_order++;
2440 fc_cpu_mask--;
2442 fc_exch_workqueue = create_singlethread_workqueue("fc_exch_workqueue");
2443 if (!fc_exch_workqueue)
2444 return -ENOMEM;
2445 return 0;
2449 * fc_destroy_exch_mgr() - Destroy an exchange manager
2451 void fc_destroy_exch_mgr(void)
2453 destroy_workqueue(fc_exch_workqueue);
2454 kmem_cache_destroy(fc_em_cachep);